SICK OF THE PUKE GOAT TRANS!!!

[dragonrider477]

my 88 mj 4.0,4x2 5 speed trans is on the way out(no big surprise huh?).i would like to swap in an automatic when it finally pukes.the trans is still working but i feel it only has maybe 10,000 miles left before it grenades(if i don't beat on it).this should give me plenty of time to get all the needed parts rounded up and make this a late summer project after the weather cools off a bit.i have an 88 xj 4x4,4.0,aw4 that has a lot of the parts i will need.what will be different,that is,what will i need to get for this swap that i won't be able to use from the xj? will i need to use the renix ecm from the xj or can i still use my present one?will the aw4 computer out of the xj work ok in the manche?how much of the wiring harness will i have to change? i am not interested in making the mj 4x4 as my yj fills that need just fine. i want to make this as simple as possible and keeping it 4x2 is simpler!btw,the mj is the long wb.

[Wildman]

Basically, to change from an BA10 to the AW4 (automatic) and keep it 2wd, you would need a 2wd, AW4. The shift linkage, TV cable, linkage at the throttle and mounting plate. TPS for the auto. Flex plate in place of the flywheel. The shifter lock out cable to the steering column, and the single brake peddle, if you want it correct. Also, the wiring harness for the automatic, both engine bay and dash, the ECM for the auto, and the auto's ECM.

 

And a new drive shaft for the auto.

 

And you would have 4.10 gears in the D35 now, and it should be 3.55 for the automatic.

 

And to go thru all this, and having a donor sitting right there (the '88 XJ) I would do the complete conversion and make it 4wd, cause you have the 4wd AW4, 231, D30, go all the way and do the 4wd :brows:

 

The only extra work would be to swap out the D30 for the straight axle, and you should swap out the D35 for the 3.55 gears.

 

If you were closer, I have a 2wd AX15 sitting in the shop. That would make it real simple ;) And 2 - 2wd AW4's.

[dragonrider477]

thanks for the detailed info.my mj was d35-3.07 open when i got it.even with the short 205-75-15 tires it was terrible.5th gear was for downhill runs only.i cannibalized the 3:55 posi internals from the xj last fall and transplanted the parts into the mj housing.btw,the xj was c-type and the mj was'nt.everything went together ok despite the mismatch and after about 5k miles it's still ok.i suppose i could put the aw4/transfer case combo in the mj and leave the rest of the 4x4 stuff off.other than the extra weight of the t/case,i would'nt see any problems.if i did that,it seems all that i would need would be a mj long box specific 4x4 rear driveshaft.if i decided at a later time to finish the 4x4 conversion,i would have a jump start on it.just out of curiousity,would i be able to use low range to the rear end without a front drive hooked up? i'm just thinking if i needed extra torque to pull something at low speed(assuming i could get the traction),i would have the extra pulling power.if so,would the d-35 explode with the extra "juice" being sent down the d-shaft?

[Wildman]

just out of curiousity,would i be able to use low range to the rear end without a front drive hooked up?

 

Sure, why not, your just changing the RPM's of the output shaft from hi - low. The front of the 231 is sealed with the yoke in place, and would just spin free.

 

would the d-35 explode with the extra "juice" being sent down the d-shaft

 

I wouldn't think so, most of us run stock D35's with no problems, and in 4wd.

 

I think once you go this far, you'll end up putting that D30 under the front and hook up the stock DS and be a full 4wd ;)

 

That will be the only thing left to finish the conversion.

[Pete M]

You're going to do all that work and then not swap in the front axle? That doesn't make any sense to me. :dunno: